Wrapping machine and associated pneumatic system

ABSTRACT

A wrapping machine for wrapping trayed food products includes a plurality of pneumatic components that are actuatable by delivery of pressurized air to the pneumatic components. A pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement is configured to reduce moisture in the pressurized air.

TECHNICAL FIELD

This application relates generally to wrapping machines used forwrapping food items and, more specifically, to a wrapping machine andassociated pneumatic system that is suited for operation in coolenvironments.

BACKGROUND

Pneumatic systems, such as those used to control components in a trayeditem (e.g., trayed meat items) wrapping machine, require consistentresponse times from all of the actuation cylinders and valves in thesystem and therefore must maintain dry air throughout the system. Waterin such a pneumatic system will cause lubricants in cylinders and valvesto break down and rust to build up on surfaces not tolerant to water.The result, assuming the cylinder or valve still functions, is typicallyslower or less consistent response times for the cylinder or valve tomove from its home point to end of travel. This scenario may jeopardizeany hard deadlines of an automated system to meet specific timingrequirements.

It would be desirable to provide an automated wrapping system with apneumatic arrangement that facilitates operation in a typical90%+relative humidity and 40 degree Fahrenheit meat processingenvironment, yet can maintain a dry air actuation system to achieveconsistent actuation response times.

SUMMARY

In one aspect, a wrapping machine for wrapping trayed food productsincludes a plurality of pneumatic components that are actuatable bydelivery of pressurized air to the pneumatic components. A pneumaticarrangement produces pressurized air for actuating the pneumaticcomponents. The pneumatic arrangement is configured to reduce moisturein the pressurized air.

In another aspect, a wrapping machine for wrapping trayed food productsincludes a plurality of pneumatic components that are actuatable bydelivery of pressurized air to the pneumatic components. A pneumaticarrangement produces pressurized air for actuating the pneumaticcomponents. The pneumatic arrangement includes first and second receivertanks connected in series along a flow path from the compressor to thepneumatic components.

In a further aspect, a wrapping machine for wrapping food productsincludes a wrap station at which food products are wrapped and a filmdispensing system for drawing out film over food products at the wrapstation. A conveying system moves food products along a path to the wrapstation. A plurality of pneumatic components are provided, eachpneumatic component actuatable by delivery of pressurized air, and apneumatic arrangement produces pressurized air for actuating thepneumatic components. The pneumatic arrangement includes a compressor,first receiver tank and second receiver tank. The compressor tankincludes an air inlet and an air outlet. The first receiver tankincludes an air inlet fluidly connected to the air outlet of thecompressor to receive pressurized air, the first receiver tank is sizedto enable water in the pressurized air to condense, the first receivertank includes a drain outlet for draining condensed water, and the firstreceiver tank has an air outlet. An air inlet of the second receivertank is fluidly connected to the air outlet of the first receiver tankto receive pressurized air. The second receiver tank is sized to enablewater in the pressurized air that enters the second receiver tank tocondense, the second receiver tank includes a drain outlet for drainingcondensed water, and the second receiver tank having an air outlet thatis fluidly connected to a path for delivery of pressurized air to thepneumatic components.

In yet another aspect, a wrapping machine for wrapping food productsincludes a wrap station at which food products are wrapped and a filmdispensing system for drawing out film over food products at the wrapstation. A conveying system moves food products along a path to the wrapstation. A plurality of pneumatic components are provided, eachpneumatic component actuatable by delivery of pressurized air, and apneumatic arrangement produces pressurized air for actuating thepneumatic components. The pneumatic arrangement includes a compressorand a receiver tank. The receiver tank includes an air inlet fluidlyconnected to the air outlet of the compressor to receive pressurizedair, and the receiver tank is sized to enable water in the pressurizedair to condense, the receiver tank includes a drain outlet for drainingcondensed water, and the receiver tank has an air outlet. The receivertank also has an air outlet fluidly connected to a path for delivery ofpressurized air to the pneumatic components. A drain valve is associatedwith the drain outlet (e.g., downsteam along a drain path that isconnected to the drain outlet). A controller is configured forcontrolling wrap operations of the wrapping machine, includingcontrolling the conveying system, the pneumatic components and thecompressor. The controller is also configured to selectively open thedrain valve (i) upon completion of a wrap sequence and/or (ii) uponstart-up of a wrap sequence.

In still another aspect, a wrapping machine includes wrap station atwhich food products are wrapped and a film dispensing system for drawingout film over food products at the wrap station. A conveying systemmoves food products along a path to the wrap station. A plurality ofpneumatic components are provided, each pneumatic component actuatableby delivery of pressurized air. A pneumatic arrangement producespressurized air for actuating the pneumatic components. The pneumaticarrangement includes a compressor with an air inlet and an air outlet,the outlet fluidly connected to a path for delivery of pressurized airto the pneumatic components. A pressurized air wand is connected to anoutlet of the path such that pressurized air produced on-board of thewrapping machine can be selectively output by the pressurized air wandunder manual control.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective front view of a wrapping machine;

FIG. 2 is a side elevation of the wrapping machine;

FIG. 3 is a schematic side view showing product movement through themachine during wrapping;

FIG. 4 is a schematic depiction of wrapping machine components and apneumatic arrangement of the machine; and

FIGS. 5 and 6 are perspective rear views of the wrapping machine.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, a food product wrapping machine 10 includes aninner frame and outer housing 12. An inlet area 14 provides a locationat which products to be wrapped (e.g., food items 16, such as meats intrays) are input to the machine for wrapping in plastic film. The inletarea 14 is part of a conveying system 18 that carries packages into themachine (right to left in FIGS. 2 and 3) and then up into a wrap station20 at which the food products are wrapped. Here the conveying systemincludes one or more horizontal conveyors 18A that feed from the frontof the machine back to an elevator mechanism 18B. A film dispensingsystem 22 is provided for drawing out film over food products at thewrap station 20 (e.g., under control of a film gripper 24 that movesleft to right in FIG. 3 in order to draw off film from one or more filmrolls 26). Where more than one film roll is provided (e.g., of differingfilm widths), an actuatable film selector 28 provides the ability toselect the desired film for a given wrap operation (e.g., depending uponsize of the food product). An actuatable film knife 30 is provided tocut the film at the appropriate time to enable the wrap operation to becompleted. The wrap station may include side clamps 32A, 32B to grip thelateral sides of the film, as well as side underfolders and a rearunderfolder (not shown).

A weighing mechanism 34 is located at the inlet area for weighing thefood product as it is placed into the machine. Once a stable weight isdetermined, the food product 16 is moved laterally into the machinethrough a light curtain imaging system 38 and past a height sensor array40 for determining size of the food product and location of the foodproduct on the conveyor. Part of the horizontal conveying system 18A mayshift be shifted (e.g., into or out of the page in FIG. 3) as necessaryto assure that the food product is properly centered when it istransferred onto the elevator mechanism 18B. After the food product ismoved up into the wrap station 20 and wrapped, the wrapped food productis conveyed by a conveyor 42 back toward the front of the machine anddeposited onto another horizontal conveyor 44, which here moves left orright (into or out of the page in FIG. 3). The conveyor 42 includes anassociated sealer belt that heats the bottom of the wrapped food productto seal the film, and a label printing mechanism 46 prints and applies apricing label to the wrapped food product. An exemplary controller 50 isshown for controlling machine operation. As used herein, the termcontroller is intended to broadly encompass any circuit (e.g., solidstate, application specific integrated circuit (ASIC), an electroniccircuit, a combinational logic circuit, a field programmable gate array(FPGA)), processor(s) (e.g., shared, dedicated, or group—includinghardware or software that executes code), software, firmware and/orother components, or a combination of some or all of the above, thatcarries out the control functions of the machine or the controlfunctions of any component thereof.

Various motors M are shown and are used primarily for movement of theconveyor components, gripper components and underfolders. However, aplurality of pneumatic components are also provided for control ofcomponents, where each pneumatic component is actuatable by delivery ofpressurized air.

In this regard, FIG. 4 shows an exemplary pneumatic arrangement 60 forthe wrapping machine. The illustrated system employs pneumatics toperform actuation of various components and utilizes a design that canremove the heat and humidity from the compressor and the environmentfrom which the compressor is pulling air. This design solves the problemof maintaining a dew point within the pneumatic system that is below theambient temperature of the environment (in this case the environment istypically the meat processing environment, which may be 50° F. or less,such as less than 46° F.).

The exemplary automated wrapping system includes a pair of pneumaticcylinders 62A, 62B to actuate the side clamps 32A, 32B, a set ofpneumatic gripper cylinders 64A, 64B, 64C to actuate the grippingoperation of the film gripper 24 (which has a center grip and two sidegrips), a pneumatic cylinder 66 to actuate the film knife assembly 30 tocut the film, a pair of film selector pneumatic cylinders 68A, 68B toselect from the two film rolls, and a pneumatic cylinder 70 to actuate alabel applier. All of these actuation points should be free from anymaterial amount of water in the pressurized air system to operate atspecific response rates required to wrap product in trays at desiredspeeds (e.g., 30 Packages Per Minute (PPM) or more). The systemcomponents described below help to develop pressure in the system andmaintain a dew point in the system that is below the ambienttemperature, even in low temperature environments.

The air flow of the system starts at the compressor 100 with arrowsindicating the flow through all key components. The compressor 100includes an air inlet and an air outlet and generates a high pressure(e.g., at least 120 PSI, such at least 130 PSI (e.g., a 135 PSI target))as it moves air from the walk-in cooler environment into a closedpressure system. To reduce overall noise, the compressor 100 may besized that is only needs to be operated at no more than a 50% dutycycle, such as at most a 40% duty cycle or at most a 35% duty cycle toprovide adequate air pressure even when the wrapping machine is wrappingat a rated high speed of 25 or more PPM. However, even at a 30% dutycycle the negative by product of the compression is heat that willaffect the dew point and should be removed, and a fan may be providedfor this purpose. The compressor 100 is also pulling in high humidityair in the walk-in cooler environment, making it more difficult tocreate a dry pressurized air flow to the components.

The illustrated fluid connections between components may be formed ofsuitable tubing (e.g., copper and/or flexible). Tubing in the systembetween the compressor and a receiver tank 102 may be of a specifiedlength and diameter (e.g., ½″ OD) to provide an adequate amount of flowof the 135 PSI system as well as a suitable surface area for thecompressed air to cool as it travels to the air inlet of a receiver tank102. An unloader valve 104 with associated pressure sensor is providedbetween the compressor 100 and receiver tank 102 to remove pressure inthe supply line between the compressor 100 and the receiver tank 102 toallow the compressor to start without back pressure. The air outlet ofreceiver tank 102 feeds to an air inlet of a receiver tank 108. Receivertank 102 includes a drain outlet 110 and receiver tank 108 includes adrain outlet 112. Drain outlet 110 feeds to a controllable drain valve114. Here, the drain outlet 112 feeds along a path 116 into receivertank 102 for eventual draining through drain outlet 110. However,alternatively drain outlet 112 could feed along a separate external path118 to the input side of the drain valve 114.

The air outlet of receiver tank 108 feeds to path that leads to an airinlet of an auto drain trap 120, which in turn has an air outlet thatfeeds to an air inlet of another auto drain trap 122. A pressureregulator 124 is positioned between the two auto drain traps and reducesthe pressure to a desired set level for component operation. The airoutlet of auto drain trap 122 feeds to a low pressure dump valve 126,which in turn feeds to a valve manifold 128 with a plurality ofcontrollable valves that enable controlled and selective delivery ofpressurized air to the various pneumatic components.

Another valve manifold 130 selectively connects the high pressure airflow to the label applier cylinder, at either side according actuationdesired. A vacuum pump 132 creates a vacuum pull along path 134 thatalso feeds through the valve manifold 130 for selectively controllingapplication of the vacuum to an label application wand 136 to hold alabel at the end of the wand.

Notably, the receiver tanks 102 and 108 are positioned, sized andconfigured such that the hot, humid, high pressure air (e.g., at least100 PSI) expands and cools since the surface of the tanks are cooled bythe meat processing environment. In one example, each receiver tank maybe cylindrical in configuration having a capacity of between about oneand about three gallons. The expansion and cooling process forcesmoisture out of the compressed air through condensation, therebylowering the moisture level in the pressurized air. The cool surfacearea of the first tank 102 causes condensation of the water as it passesthru the tank inlet, which condensation falls to the bottom of the tank102. The air is subsequently cooled further within the tank during thisfirst stage of condensation and cooling. Water can collect on the bottomof the tank 102. The water is expelled on a selective basis undercontrol of the drain valve 114. Alternatively, the water in tank 108drains along path 118. By using two receiver tanks instead of one, thelikelihood of blow through of condensed water is reduced, and theoverall tank surface area is increased and/or more effectively utilized.A pressure relief valve 115 may be provided on one or both of thereceiver tanks to limit pressure within the tanks, and a pressure gauge117 may also be provided for visual inspection by operators.

The high pressure air then enters the second receiver tank 108 forsubsequent further cooling of the pressurized air and furthercondensation of remaining water in the pressurized air. Tank 108 islocated above tank 102, and this condensed water is freely drained bygravity into the bottom receiver tank 102 for subsequent removal undercontrol of the drain valve. The combined cooled surface area of the tworeceiver tanks 102 and 108, the volume of the tanks to handle watercondensation and drain the water, and the high pressure force waterdroplets to separate from the pressurized air. The two downstream autodrain traps 120 and 122 provide a final filtering of the air in thesystem and expel any remaining condensed water particulates outside ofthe closed air system. The pressure reduction between traps 120 and 122and resulting expansion of the air results in a lower dew point of thepressurized air at the downstream side of regulator 124. The result is apressurized air flow from drain trap 122 having a dew point below thetemperature of the ambient working environment of the machine (e.g.,below 50° F.), which pressurized air is made available to the downstreamcomponents through the valve manifold 128. Because the dew point of thepressurized air is lower than the relatively cool temperature of theambient environment, moisture condensation on the downstream side of theregulator 124 is significantly reduced and/or substantially eliminatedfrom the system. The controller 50 is connected for selective control ofeach valve.

The drain valve 114 may be opened on a predefined basis for draining ofcondensed water. By way of example, in one implementation the drainvalve 114 may be momentarily opened (e.g., for less than one second) topermit draining each time the wrapping machine is started to initiate awrap sequence or operation (e.g., when a start button 160 (FIG. 2) ispushed, or as part of an machine initialization sequence carried outresponsive to pushing of the start button 160). In another example, thedraining may take place each time a wrap sequence or operation isstopped (e.g., when the machine is turned off). Periodic draining (e.g.,every X minutes) or draining based upon operating time (e.g., after Yminutes of compressor operation) could also be implemented.

The compressor 100 and receiver tank volume can be collectively sizedsuch that adequate air pressure is made available for all pneumaticcomponents to operate properly as necessary for sequential wrappingoperations at a rated high speed of at least 25 PPM (such as at least 30PPM), while at the same time requiring the compressor to be operated atno more than a 50% duty cycle (e.g., at most a 40% duty cycle or at mosta 35% duty cycle). This reduces overall heat production by thecompressor and also enables overall quieter operation of the machine. Apressure sensor may be used to control when the compressor is turnedON/OFF.

As seen in the rear perspectives of FIGS. 5 and 6, the compressor 100and vacuum pump 132 may be located in a rear compartment 170 of themachine 10, where the rear compartment includes one or more louveredcover panels 172 that enable ventilation of the compartment. A fan maybe provided for moving air through the compartment if needed for heatreduction.

The heat by product of the compressor 100 and/or vacuum pump 132 mayalso be put to use to warm film and the sealer belt by heat capture andflow along paths 140, 142 (FIG. 4). Due to the cold environment of thewalk-in cooler film can be cold and will stretch less than desiredduring wrap of a product. Ideal wraps occur when the film temperature ismaintained at or above sixty degrees Fahrenheit. The sealer belt of thesystem also requires a substantial amount of heat (upwards of 300degrees Fahrenheit) to be applied to the bottom of a wrapped producttray to seal the film. The compressor 100 and the vacuum pump 132generate heat that may be captured and output (e.g., as a heated airflow) to the film and/or sealer belt areas of the machine to passivelyheat these areas.

Notably, and referring again to FIG. 4, the pressure regulator 124provides a higher pressure zone upstream of the pressure regulator 124and a lower pressure zone downstream of the pressure regulator 124. Byway of example, a pressure in the higher pressure zone may be at least120 PSI (per above), and a pressure in the lower pressure zone may nomore than 75 PSI (e.g., no more than 60 PSI, such as a 50 PSI target).

As shown, a pressurized air cleaning/drying wand 150 may be connected toa high pressure outlet 152 of the higher pressure zone. The highpressure outlet 152 may include a quick disconnect coupler to which aflexible feed tube 154 of the pressurized air cleaning/drying wand isconnected for this purpose. The operator may selectively use the wand150 for cleaning of the wrapping machine and/or the area around thewrapping machine. An openable/closeable valve 106 (e.g., manual levervalve or electrically/electronically controllable valve) may be providedalong the flow path to the high pressure outlet 152 for controllingwhether high pressure air is present at the outlet 152. The operatoropens the valve when there is desire to use the wand 150.

It is to be clearly understood that the above description is intended byway of illustration and example only, is not intended to be taken by wayof limitation, and that other changes and modifications are possible.

What is claimed is:
 1. A wrapping machine for wrapping food products,comprising: a wrap station at which food products are wrapped; a filmdispensing system for drawing out film over food products at the wrapstation; a conveying system for moving food products along a path to thewrap station; a plurality of pneumatic components, each pneumaticcomponent actuatable by delivery of pressurized air; a pneumaticarrangement for producing pressurized air for actuating the pneumaticcomponents, the pneumatic arrangement including: a compressor includingan air inlet and an air outlet; a first receiver tank having an airinlet fluidly connected to the air outlet of the compressor to receivepressurized air, the first receiver tank sized to enable water in thepressurized air to condense, the first receiver tank including a drainoutlet for draining condensed water, the first receiver tank having anair outlet; a second receiver tank having an air inlet fluidly connectedto the air outlet of the first receiver tank to receive pressurized air,the second receiver tank sized to enable water in the pressurized airthat enters the second receiver tank to condense, the second receivertank including a drain outlet for draining condensed water, the secondreceiver tank having an air outlet that is fluidly connected to a pathfor delivery of pressurized air to the pneumatic components.
 2. Themachine of claim 1 wherein the second receiver tank is positioned abovethe first receiver tank.
 3. The machine of claim 2 wherein the drainoutlet of the second receiver tank is connected to a drain inlet of thesecond receiver tank such that water drained from the first receivertank passes through the first receiver tank.
 4. The machine of claim 1wherein the drain outlet of the first receiver tank is spaced from theair outlet of the first receiver tank to limit moisture blow through tothe second receiver tank, and the drain outlet of the second receivertank is spaced from the air outlet of the first receiver tank to limitmoisture blow through to the path.
 5. The machine of claim 1, furthercomprising: a first auto drain trap along the path and having an airinlet fluidly connected to the air outlet of the second receiver tank,the first auto drain trap configured for capturing water and particulatein the pressurized air, the first auto drain trap having an air outlet.6. The machine of claim 5, further comprising: a second auto drain traphaving an air inlet fluidly connected to the air outlet of the firstauto drain trap, the second auto drain trap configured for capturingwater and particulate in the pressurized air, the second auto drain traphaving an air outlet.
 7. The machine of claim 6, wherein the air outletof the second auto drain trap is fluidly connected to the plurality ofpneumatic components.
 8. The machine of claim 1, wherein one or morecontrollable air valves fluidly connect the air outlet of the secondreceiver tank to the plurality of pneumatic components to enableselective delivery of pressurized air from the second receiver tank tothe pneumatic components.
 9. The machine of claim 8 wherein the drainoutlet of the first receiver tank and the drain outlet of the secondreceiver tank feed to a common and controllable drain valve.
 10. Themachine of claim 9, wherein a controller is connected for selectivecontrol of each of the air valves, selective control of the drain valve,and selective operation of the compressor.
 11. The machine of anypreceding claim 8, wherein a pressure regulator is positioned betweenthe air outlet of the second receiver tank and the controllable airvalves to provide a higher pressure zone upstream of the pressureregulator and a lower pressure zone downstream of the pressureregulator.
 12. The machine of claim 11, wherein a pressure in the higherpressure zone is at least 120 psi and a pressure in the lower pressurezone is no more than 75 psi.
 13. The machine of any preceding claim 1,wherein a first heat transfer arrangement is configured to transferwaste heat of the compressor to one or both of a sealer belt film sealzone and/or a film roll supply location.
 14. The machine of claim 13,wherein a vacuum pump is fluidly connected for control of a vacuumactuated component, wherein a second heat transfer arrangement isconfigured to transfer waste heat of the vacuum pump to one or both ofthe sealer belt film seal zone and/or the film roll supply location. 15.The machine of claim 1, wherein the drain outlet of the first receivertank and the drain outlet of the second receiver tank feed to a commonand controllable drain valve, a controller is connected for selectivecontrol of the drain valve and selective operation of the compressor,the controller configured to selectively open the drain valve.
 16. Themachine of claim 1, wherein the compressor and total volume of the firstand second receiver tanks are collectively sized such that sufficientair pressure is made available for all pneumatic components top operateproperly as necessary for sequential wrapping operations at a rated highspeed of at least 25 packages per minute, while at the same timerequiring the compressor to be operated at no more than a 50% dutycycle.
 17. A wrapping machine for wrapping food products, comprising: awrap station at which food products are wrapped; a film dispensingsystem for drawing out film over food products at the wrap station; aconveying system for moving food products along a path to the wrapstation; a plurality of pneumatic components, each pneumatic componentactuatable by delivery of pressurized air; a pneumatic arrangement forproducing pressurized air for actuating the pneumatic components, thepneumatic arrangement including: a compressor including an air inlet andan air outlet; at least one receiver tank having an air inlet fluidlyconnected to the air outlet of the compressor to receive pressurizedair, the receiver tank sized to enable water in the pressurized air tocondense, the receiver tank including a drain outlet for drainingcondensed water, the receiver tank having an air outlet fluidlyconnected to a path for delivery of pressurized air to the pneumaticcomponents; a drain valve associated with the drain outlet; a controllerconfigured for controlling wrap operations of the wrapping machine,including controlling the conveying system, the pneumatic components andthe compressor, the controller configured to selectively open the drainvalve (i) upon completion of a wrap sequence and/or (ii) upon start-upof a wrap sequence.
 18. A wrapping machine for wrapping food products,comprising: a wrap station at which food products are wrapped; a filmdispensing system for drawing out film over food products at the wrapstation; a conveying system for moving food products along a path to thewrap station; a plurality of pneumatic components, each pneumaticcomponent actuatable by delivery of pressurized air; a pneumaticarrangement for producing pressurized air for actuating the pneumaticcomponents, the pneumatic arrangement including: a compressor includingan air inlet and an air outlet, the outlet fluidly connected to a pathfor delivery of pressurized air to the pneumatic components; and apressurized air wand connected to an outlet of the path such thatpressurized air produced on-board of the wrapping machine can beselectively output by the pressurized air wand under manual control. 19.The wrapping machine of claim 18, wherein the pressurized air wandincludes a flexible hosing to enable movement of the pressurized airwand.
 20. The wrapping machine of claim 18, wherein a pressure regulatoris positioned between the air outlet of the compressor and the pneumaticcomponents to provide a higher pressure zone upstream of the pressureregulator and a lower pressure zone downstream of the pressureregulator, and the pressurized air wand is connected to a high pressureoutlet of the higher pressure zone.
 21. The machine of claim 20, whereinthe high pressure outlet includes a quick disconnect coupler to which afeed tube of the pressurized air wand is connected
 22. The machine ofclaim 20, wherein a pressure in the higher pressure zone is at least 100psi and a pressure in the lower pressure zone is no more than 60 psi.